The present invention relates to a disc changer in which a plurality of discs are installed to select any one of the discs for recording/playing.
In a conventional disc changer, a disc holding means is configured to house a plurality of subtrays in a stocker having a plurality of shelves, and a vertical driving means for selecting the position of an arbitrary disc is configured to drive all of the stocker, the plurality of subtrays, and the plurality of discs in the vertical direction.
In the conventional disc changer, however, while the vertical driving means for driving a disc holding means to select an arbitrary disc position is effecting driving, the large weight of the stocker having the plurality of shelves and the disc holding means for driving all of the plurality of subtrays and discs may cause a vertical driving motor to consume a large amount of energy or cause falling of finished discs or inappropriate vibration. In addition, the large number of parts increases costs.
Then, a recently contemplated disc changer comprises a disc holding means 204 for detachably supporting a plurality of spacers 203 on a pair of spindles 201 and 202 using a holding claw 200, a vertical driving means 205 for driving the spacers 203 in the vertical direction to select arbitrary positions of a plurality of discs 223 and 224 held by the plurality of spacers 203, a spindle driving means 206 for driving the holding claw 200 to engage and disengage the plurality of spacers 203 with and from the upper spindle 201, a horizontal transfer means 207 for transferring discs 223 and 224 to a recording/playing position E from arbitrary spacers 203 held by the holding claw 200, while supporting the discs on subtrays 225, and a disc clamp means 208 for clamping the discs 223 and 224 at the recording/playing position E, for example, as shown in FIGS. 43 to 45.
The disc changer of this configuration can drive in the vertical direction the plurality of spacers 203 and plurality of discs 223 and 224 installed on both spindles 201 and 202 to shift the arbitrary disc 223 or 224 from the spindle 201 or 202 to the recording/playing position E, then to an unloading position G, and back to a housing position F on the spindle 201 or 202, and can select the arbitrary disc 223 or 224 for recording/playing. Thereby, this configuration eliminates the needs for a stocker having a plurality of shelves or a plurality of subtrays to reduce the weight and costs, and provides a disc changer having excellent housing and operating capabilities.
In this disc changer, however, separate elevating cams 209 and 210, connecting mechanisms 211 and 212 and lock means 213 and 214 were used to execute driving including the elevation and lowering of the disc holding means 204 using the spindles and the elevation and lowering of the disc clamp means 208 to clamp the discs 223 and 224 at the recording/playing position E. Consequently, the apparatus was complicated and loads of the elevating cams 209 and 210 enormously varied when the spindles 202 of the disc holding means 204 and the disc clamp means 208 were simultaneously driven to elevate and lower, respectively, resulting in problems such as an unstable operation during the elevating driving caused by an insufficient driving force and a high operation noise during the lowering driving.
Furthermore, since a horizontal transfer means 207 for transferring a tray 215 depended on driving based on the engagement between a single driving gear 216 and racks 217 and 218 provided for each part, the driving was carried out at a single reduction gear ratio to preclude the reduction gear ratio from being adjusted to account for operation loads, thereby preventing requirements for both the operation time and load margin from being met.
Furthermore, due to the independency between a vertical driving system for driving in the vertical direction the spacers 203 holding the discs 223 and 224 and a horizontal driving system for driving the elevation and lowering of the spindle and transferring the tray 215, separate driving sources had to be provided for these systems, and intermediate gears were also required. As a result, the number of required parts was increased to increase the size and costs of the apparatus.
Moreover, in order to compactify the changer, an attempt was made to reduce the distance between the recording/playing position E and the disc holding position F so that the disc 224 at the recording/playing position E appeared to partly overlap the disc 224 at the disc holding section as seen from above. Due to vibration, however, the disc housed adjacent to the disc 224 under recording/playing at the disc holding section contacted the disc 224 under recording/playing to cause an accidental track shift or to damage the disc.
Furthermore, in order to integrate the independent driving sources into a single common source, an attempt was made to allow part of the gear train to be shared by both the driving system for the vertical driving of the spacers 203 and the horizontal driving system and to use a gear that slided in the axial direction to select the engaged driving system, as a means for switching the driving. When, however, the gear sliding in the axial direction started to engage with the gear of the driving system upon driving switching, it was blocked and failed to effect switching, causing the apparatus to stop with an abnormal noise.
Moreover, the disc clamp means 208 was elevated from and lowered to the recording/playing position E by engaging a lateral pair of pins 221 on a disc playing means 220 with cam grooves 219 formed in right and left elevating cams 210. In this case, during elevation and lowering, the disc playing means 220 might be rotationally moved via the pins 221. If two left pins and one right pin were used instead of the lateral pair of pins 221 to solve this problem, the stroke of the right and left elevating cams 210 increased, resulting in another new problem that size of the apparatus increased.
Furthermore, when the tray 215 was opened to change the disc, a disc of a small diameter 223 such as 8 cm might accidentally fall into the apparatus due to a large opening 222 in the front surface of the apparatus.
It is an object of this invention to provide a small disc changer of a simple configuration that can avoid operation noise or unstable operations due to the variation of operation loads, that enables a disc playing means to be elevated and lowered with its posture maintained in the horizontal direction, and that can prevent a disc from accidentally falling into the apparatus when a tray is opened.
To achieve this object, a disc changer according to this invention comprises an apparatus body, a disc transfer means for transferring a disc in the apparatus body between a disc housing position and a disc playing position, and a vertical pair of spindles detachably holding a plurality of spacers at the disc housing position, and comprises a disc holding means capable of relatively elevating and lowering the spindles and driving the spacers in the vertical direction to deliver the disc to the disc transfer means, a disc playing means supported on the apparatus body at the disc playing position so as to be able to elevate and lower, an elevating means for elevating and lowering the spindles and the disc playing means, and a horizontal driving means capable of driving the disc transfer means and the elevating means, wherein the elevating means is configured so that a single part simultaneously effects the driving of the spindles and the disc playing means.
This invention can drive in the vertical direction the plurality of spacers and plurality of discs installed on both spindles to shift the arbitrary disc from the spindle to a disc playing position, then to an unloading position, and back to a disc housing position on the spindle, and can select the arbitrary disc for recording/playing. This configuration eliminates the needs for a stocker having a plurality of shelves or a plurality of subtrays to reduce the weight and costs, and provides a disc changer having excellent housing and operating capabilities.
Besides, the same part is used to drive the elevation and lowering of the spindles of the disc holding means and the disc playing means to allow the elevation and lowering timings for both components to coincide easily in order to enable elevation and lowering without a change in the gap between a played disc being elevated or lowered and a held disc in the housing section, thereby preventing discs from contacting each other during elevation or lowering.
One embodiment of this invention is configured so that a plate having a cam groove drives the elevation and lowering of the spindles of the disc holding means and the disc playing means.
According to this embodiment, the spindles and the disc playing means can be elevated and lowered using a simple configuration in such a way as to maintain coincident timings.
Another embodiment of this invention uses in part of the elevating means for the spindles and the disc playing means, a cam gear connected to a lateral pair of plates via an intermediate gear to rotate in synchronism with the movement of the plates.
Even if the pitch between the pins provided in the lateral direction relative to the disc playing means is different from the width-wise pitch of the pins provided in the lateral direction relative to a elevating base for the spindles, this embodiment enables elevation and lowering using the simple configuration without a change in such a way as to maintain coincident timings for both components.
In addition, according to the disc changer of this invention, the horizontal driving means is composed of a driving gear connected to the driving source via a speed reduction mechanism, a driving rack meshing with the driving gear, and a speed-increasing gear rotatably supported on the driving rack. The speed-increasing gear is a double-gear unit composed of a larger and a smaller gears having the same number of teeth and different modules, and the smaller gear engages with a rack provided in the elevating means, while the larger gear engages with a rack provided in the disc transfer means.
According to this invention, by freely selecting the module, that is, the pitch diameter between the larger and smaller gears having the same number of teeth, the driving of the tray and the driving of the elevating means for the spindle and the disc playing means, the two driving types involving significantly different operation loads, can be freely set so that a driving force transmitted from the common driving source is suitable for the loads on the tray and the elevating means and the required speeds.
Furthermore, the disc changer according to this invention comprises a switching gear connected to the driving source via the speed reduction mechanism and supported so as to slide in the axial direction and that can selectively mesh with either a gear train provided in the horizontal driving means or a gear train provided in the vertical driving system for the spacers; and a drive-switching means for allowing the switching gear to slide in the axial direction, and has a switching mode that includes at least the rotational driving, stop, and reverse driving of the switching gear and that is available during the sliding of the switching gear effected by the drive-switching means.
According to this invention, the switching gear switching between the two driving systems meshes with the gear train in one of the driving systems while carrying out a small number of repetitions of rotations, stoppages, and reverse rotations, thereby preventing the tooth tips from mutually abutting to obstruct the sliding of the switching gear. This configuration enables the sharing of the driving source and the partial sharing of the driving systems to reduce the number of required parts and thus the size of the apparatus.
One embodiment of this invention uses in part of the common speed reduction mechanism, an elastic belt each end of which is passed around each of a pair of pulleys.
When the elastic belt is used in part of the speed reduction mechanism according to this embodiment, the lateral pressure of the belt remains in the driving system after driving is stopped, thereby increasing loads effected when the switching gear is disengaged from the teeth of the driving system to which the switching gear has been connected prior to switching. Thus, the repetitions of rotations, stoppages, and reverse rotations are effective in eliminating this advantage.
Another embodiment of this invention provides control such that when the driving is switched, the switching gear is initially rotated in the direction opposite to the rotating direction of the driving system to which the switching gear has been connected prior to switching, the rotating direction existing immediately before the stoppage of the driving system.
This embodiment can stop the rotation caused by driving inertia after the stoppage of driving to reduce the standby time from the stoppage of driving prior to switching until the switching mode is entered, thereby reducing the disc change time. In addition, in the above configuration with the elastic belt, this embodiment is particularly effective in reducing switching loads effected by the lateral pressure of the belt.
Furthermore, the disc changer according to this invention comprises a disc gap maintaining means that can advance between housed discs vertically adjacent to a played disc.
According to this invention, even if the disc housing and playing positions are located closer to position the housed discs and the played disc in such a way that the discs appear to overlap one another in a top view, in order to compactify the apparatus, the gap maintaining means advances into the gap between the housed discs adjacent to the played disc in the vertical direction to preclude the gap from being narrowed despite vibration, thereby preventing an accidental track shifts or damage to the disc caused by the contact between the played disc and the housed disc.
According to a preferred embodiment of this invention, the gap maintaining means comprises levers, so it can be simply positioned and can stably maintain the constant gap using a simple configuration. In addition, since the gap maintaining means is configured to be driven by the elevating means, it can be driven without deviating from the elevating and lowering timings for the spindles provided by the elevating means and the elevating and lowering timings for the disc playing means. The arrangement of the gap maintaining means between the disc housing position and the disc playing position allows the gap to be maintained close to both the disc playing and housing positions, thereby enabling accurate gap maintenance. Furthermore, sections of the disc gap maintaining means that advance between the adjacent discs are provided at two positions approximately laterally symmetrical about the center of the disc to prevent the housed discs at the lateral advancing section from inclining relative to the placed disc, thereby enabling the gap to be stably maintained despite adverse effects such as the inclination and vibration of the apparatus. Besides, if the advancing sections of the disc gap maintaining means are composed of planes with a sharp junction, when their tips advance between the two housed discs adjacent to the played disc in the vertical direction, they can target a single point in the gap between the discs to provide margins for displacements of the advancing gap maintaining means. In addition, if the disc contact surfaces are smooth planes, sliding loads on the end surface of the disc can be reduced to prevent the gap maintaining means from contacting the disc end and then being caught on it.
In addition, the disc changer according to this invention comprises an apparatus body, a disc playing means supported on the apparatus body at the disc playing position so as to be able to elevate and lower, an elevating means for elevating and lowering the disc playing means, and a horizontality maintaining means for regulating the elevating and lowering postures of the disc playing means. The elevating means comprises a lateral pair of plates supported so as to slide relative to the apparatus body, and a connecting lever rotatably supported on the apparatus body to connect the lateral pair of plates together. The horizontality maintaining means comprises a rotating shaft extending in parallel with the sliding direction of the plate and rotatably supported on the apparatus body, a horizontality maintaining lever that can rotate with the rotating shaft, and a engaging section provided on the horizontality maintaining lever and parallel with the rotating shaft. The engaging section slidably engages with an engaging groove provided in the disc playing means to rotationally move around the axis of the rotating shaft during the elevation and lowering of the disc playing means.
According to this invention, the elevating means effects driving to allow the right and left plates to slide in opposite directions to synchronously elevate or lower both pins engaged with the cam groove, by an equal amount, thereby enabling the disc playing means to be elevated and lowered. When this disc playing means elevates or lowers, the engaging section, elevates and lowers with the disc playing means due to its engagement with the engaging groove while rotationally moving the horizontality maintaining lever with the engaging section integrated therewith, together with the rotating shaft, thereby allowing the engaging section to rotate around the axis of the rotating shaft. This configuration can elevate and lower the disc playing means with the other movement, that is, the rotational movement of the disc playing means restrained by the horizontality maintaining lever with the rotating shaft held in the horizontal direction, thereby enabling the rotating shaft of the horizontality maintaining lever to be held in the horizontal direction when the disc playing means elevates and lowers.
One embodiment of this invention is configured so that the disc playing means is elevated and lowered by engaging the lateral pair of pins provided on the disc playing means with the lateral pair of cam grooves provided in the elevating means, respectively.
According to this invention, the elevating means requires only the single lateral pair of cam grooves, thereby reducing the sliding stroke of the elevating means and thus the size of the disc playing apparatus.
Furthermore, the disc changer according to this invention provides a disc playing apparatus which comprises an apparatus body, a tray that can move between a first position in the apparatus body at which the disc can be played and a second position at which the tray protrudes from the apparatus body so that the disc can be changed, and at least one covering means rotatably supported on the apparatus body to cover at least part of an opening formed due to the protrusion of the tray to the second position. The covering means has levers rotationally moving in response to the movement of the tray, and having a pair of protruding portions arranged at positions approximately laterally symmetrical around the center of the disc on the tray and provided at an interval smaller than the outer diameter of a small-diameter disc. The opposite ends of the protruding portions each have an uneven surface formed like saw teeth.
According to this invention, when the tray is allowed to protrude to move from the first position to the second position, the cams on the tray automatically rotationally moves the levers so as to stand. Thus, the protruding portions integrated with both levers can cover part of the opening formed due to the protrusion of the tray to the second position. Consequently, when the disc is manually removed from the tray or changed even if the disc accidentally falls from the opening toward the inside of the apparatus body, the end of the disc is caught between the uneven surfaces formed like saw teeth in the pair of protruding portions provided at the interval smaller than the outer diameter of the small-diameter disc, thereby preventing the disc from falling into the apparatus body.
One embodiment of this invention is configured so that the cams provided on the tray rotationally move the levers during the opening and closing of the tray.
According to this embodiment, even if the disc is pressed toward the interior of the apparatus body while contacting the levers, the levers are precluded from rotationally moving and falling down to prevent the disc from falling into the apparatus body.